THE ASCLEPIAS TRIBE. 183 



the enchanted tree, which so surprised Tancred in 

 the sorcerer's wood — 



** When, dreadful to his view ! 

 The wounded bark a sanguine current shed, 

 And stain'd the grassy turf with streaming red." 



This milky hlood, whether white, red, or any other 

 colour, abounds in the substance called Caoutchouc or 

 Indian Rubber, a large proportion of which is actually 

 procured from plants botanically related to the As- 

 clepias. 



You will readily distinguish the calyx, which con- 

 sists of six, narrow, hairy sepals, spreading back from 

 the corolla {Plate XLV. '2. Jig. 5. a,). Their purple 

 colour betrays the petals (Jig. 2. a.), which spread 

 widely away from the centre, adhering at the base 

 only, into a short tube, and therefore constituting a 

 monopetalous corolla. From the middle of the tube 

 there rises a pentagonal column (Jig. 2. b.), form- 

 ing the base of five other concave petals (Jig. 2. c), 

 which stand erect, and collect into a sort of pink 

 coronet {corona) to the flower ; from the inside of each 

 of these coronet-petals, springs a firm, solid horn, 

 curving forwards towards the centre (Jig. 3. & 4.). 

 The monopetalous corolla is therefore composed of 

 two whorls of petals, of which the outer arc flat 

 and spreading, the inner concave, erect, and horned 

 internally. 



Cut away the true petals and those of the coronet ; you 

 will find that the pentagonal column consists of five pur- 

 ple-green anthers (Jig. 5. c), having no filaments, where 



